Conventionally, various kinds of sound absorbing sheets have been fabricated using polyester air-permeable polymer, glass wool, and the like. Further, Korean Patent Laid-open Publication No. 10-2002-0044600 discloses a technique of fabricating a layer paper for impregnation into a composite floor sheet including cellulose, polyester and PVA as main components. However, these products enhance absorption performance using mechanical properties and air-permeability of materials, thereby causing a complicated fabrication process and limited functions as sound absorbing sheets. Further, when sound absorbing sheets are made thicker in order to resolve these problems, another problem arises in that thick sheets occupy more space and require substantial manufacturing costs.
Therefore, there is a need for a new technique of fabricating sound absorbing sheets having excellent absorption performance through adjustment of mechanical properties.